/*
 *  Copyright 2017 Alexey Andreev.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.teavm.parsing;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.teavm.model.ClassHolder;
import org.teavm.model.ClassHolderSource;

public class CompositeClassHolderSource implements ClassHolderSource {
    private List<ClassHolderSource> innerSources;
    private Map<String, ClassHolder> cache = new HashMap<>();

    public CompositeClassHolderSource(List<ClassHolderSource> innerSources) {
        this.innerSources = new ArrayList<>(innerSources);
    }

    @Override
    public ClassHolder get(String name) {
        return cache.computeIfAbsent(name, n -> {
            for (ClassHolderSource innerSource : innerSources) {
                ClassHolder cls = innerSource.get(n);
                if (cls != null) {
                    return cls;
                }
            }
            return null;
        });
    }
}
